Pressurized sources of hot and cold water supplies for use in buildings, such as residences, are of relatively recent origin, most major developments of which probably occurred during the nineteenth century. In the early development, separate valves and spouts were employed and mixing occurred in a basin, such as a bathroom lavatory, tube, or kitchen sink. These are still used with laundry tubs. Later, the valves were incorporated into a unitary assembly with a single outlet or spout in which mixing occurs before discharge to the basin, which is a type now commonly in use. When employed with a shower, the outlet is usually connected to a shower head by a conduit of desired configuration. Such valve assemblies became standardized as to certain plumbing dimensions so that they would interchangeably fit basins furnished by various manufacturers (or vice versa). This standardization consisted, in the main, of providing basins with apertures in their surrounding surface or rim, usually adjacent the rear or wall side of the basin, in which the assembly is affixed. Present lavatories are often provided with three aligned apertures, the central aperture receiving a drain control rod and the outer two receiving integral conduits to which the water supplies are connected. Kitchen sinks are often provided with more than three apertures, at least one of which may receive an accessory. In any event, the apertures are predetermined by the basin manufacturer and the user is restricted to a selection of available basins and a selection of valve assemblies which may be employed therewith. While the selection within such combinations is quite wide and satisfies many users, it is nevertheless, restrictive. For example, if the user desires the spout in a rear corner of a basin rather than centrally thereof and valve controls disposed somewhat remotely adjacent the front edge thereof, such arrangement departs from the available standardization.
A recent refinement of the two valve single spout discharge assembly referred to comprises a single control for the two valves, which, by operating same in selected directions, controls temperature and discharge rate. Neither of the types referred to, however, are normally provided with an automatic temperature control valve. In the former, the hot and cold water valves are opened to meter the proper ratio of flow to obtain a desired temperature at which it will normally remain. If it is desired to change the discharge rate, both valves must be readjusted. In the latter type, a single control knob or handle has two differing motions. One motion preportions the hot and cold water and the other controls the discharge rate of the mixed water.
As will subsequently appear, the present invention further differs from the foregoing arrangement in that an automatic temperature mixing valve is provided which delivers water at a selected temperature at all flow rates and its discharge flow rate is controlled by a hydraulic servo-motor controlled by servo valves which may be disposed remotely, at will, from the mixing valve and spout.